Koushaku Fujin Lady Sapphire no Himitsu

"I want you to be my wife and the mother of this child." One day, Sapphire comes across David, a little boy with amnesia, and she takes him into her care. Despite not being a real family, they live happily together until Duke Krist Galbraith, the police chief, appears on her doorstep, claiming to be David's father. Upon seeing David's reluctance to leave Sapphire, Krist proposes marriage to her. However, Sapphire harbors a secret she cannot share with anyone. If it is revealed, not only will Krist divorce her, but she could also face immediate execution! (Source: POCKET COMICS) Note: Includes one extra chapter.